• Cartoon and Animation Studies
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• s.16
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• pp.21-32
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• 2009

This study provides an empirical analysis of box office performance for animation movies released in Korea between 2003 and 2008. Two dependent variables are both the number of audiences in the whole country and the number of audiences in Seoul. Such independent variables are employed : power of distributors, the number of screens, release time, sequel/remake, awards, film ratings, nationality, online reviews, and critics' reviews. For the total number of audiences in the whole country, significant variables are the number of screens, the power of USA distributors, Summer release, and online reviews. Since there is no analysis for box office performance for animation movies released in Korean theaters, this study will be considered to be meaningful.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.337-338
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• 2006

The purpose of this study is to find out main factors affecting public enterprise's environment, which improves the performance of public enterprise. In detail, under the premises of keeping publicity in Korea Electricity Industry, the main target of this study is to seek after factors enhancing entrepreneurship and deals with publicity which is related with entrepreneurship. Questionnaires are distributed to the employee of public enterprise, public servants, and civil corps. A total of 553 copies are collected. The main contents of questionnaires are related with the effect of publicity and entrepreneurship by government control, competitive environment, and shareholding structure in Korea Electricity Power Corporation(KEPCO). The results of this survey are as follows : First, government control is negatively related to the entrepreneurship while it is positively related to the publicity. Second, this survey shows that competitive environment has a positive influence on promoting both publicity and entrepreneurship. Third, this survey in connection with shareholding structure indicates that present structure in KEPCO has a positive effect on publicity but negative effect on entrepreneurship. According to this empirical results, it is verified that the main issues on the performance of KEPCO are related with the level of government control and competitive environment in its industry.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.4
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• pp.167-174
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• 2018

The geothermal heat pump systems were installed for heating and cooling of public buildings in Jincheon Eco-friendly Energy town. The heat pump system was operated at night to save on operational costs, and the cold heat was stored in thermal energy storage (TES). In this study, the performance of geothermal heat pump systems with the TES during the summer season was analyzed, and the operational costs with and without the TES were compared. The electric chiller model was used to simulate a heat pump applied without the TES system. Electric rates of each system were measured to calculate operational costs. When the TES is used in the air conditioning system, the electric load (30.4 MWh) calculated in the daytime can move to off-peak load time, and the operational cost is reduced by 36~54%.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.119-125
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• 2018

The tropical forests in developing countries are faced with the problem of illegal exploitation of trees. However, dearth of empirical means of expressing the dimensions, structure, quality and quantity of a removed tree has imped conviction of offenders. This study aimed at developing a model that can effectively estimate individual tree basal area (BA) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six $25m{\times}25m$ temporary sample plots (TSPs) were laid randomly in six age strata; 26, 23, 22, 16, 14, and 12 years specifically. BA, Ds and diameter at breast height were measured in all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem cross-sectional areas. Six basal area models were fitted and evaluated. The BA-Ds relationship was best described by power model which gave least values of Root mean square error (0.0048), prediction error sum of squares (0.0325) and Akaike information criterion (-15391) with a high adjusted coefficient of determination (0.921). This study revealed that basal area estimation was realistic even when the only information available was stump diameter. The power model was validated using independent data obtained from additional plots and was found to be appropriate for estimating the basal area of Tectona grandis stands in Omo Forest Reserve, Nigeria.

• Journal of Information Technology Applications and Management
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• v.15 no.3
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• pp.169-194
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• 2008

Recently, the concept of web site stickiness receives attention as a measure of strategy to influence user's visit and behavior on web sites. Web site stickiness means site visit frequency and stay duration. This study investigates the moderating effect of espoused national cultural values on Internet community stickiness with the assumption that dimensional values of national culture can be internalized as individual’s espoused values. Espoused values (i.e., espoused national cultural values) are defined as the degree to which an individual embraces the values of his or her national culture. Our findings can be summarized as follows. First, femininity and power distance moderate the influence of user participation on Internet community stickiness. Second, uncertainty avoidance and power distance moderates the effect of social influence on Internet community stickiness. However, femininity and collectivism do not moderate the effect of social influence on Internet community stickiness. Third, uncertainty avoidance, femininity, and collectivism moderate the influence of network effect on Internet community stickiness. Fourth, masculinity does not moderate the influence of usefulness on Internet community stickiness.

• Journal of the Korea Fashion and Costume Design Association
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• v.14 no.2
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• pp.185-198
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• 2012

This study aims to find out the influential factors and the relative power of these factors on the clothing purchase decision in internet shopping mall. For this purpose, this study surveyed 500 male and female consumers in their 20's~40's for empirical analysis who have ever purchased clothing through internet shopping malls. Respondents are selected using the convenience sampling through internet survey in August 2011. For statistical analysis descriptive statistics, reliability analysis, factor analysis and regression analysis are carried out using SPSS for Windows 12.0. The results are as follows. First, purchase decision is significantly affected by the expressional/physical properties of the product and product pictures. Second, purchase decision is significantly affected by the usefulness of shopping mall and the importance of purchase. Third, in consumer related factors, product value awareness, reliability of shopping mall, clothing involvement, psychological/economical perceived risks and age affect purchase decision. Fourth, in the regression analysis of the above significant variables on purchase decision, the order of power of these influential factors is expressional/physical properties of product, the importance of purchase, product picture, age and clothing involvement. The results of this study will help internet fashion enterprises to handle the variables of product, shopping mall, and consumer related for enhancing the purchase rate.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.49-55
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• 2014

In this study, boiler tube thickness measurement and numerical analysis were conducted for standard 500MW coal-fired power plant in order to research the mechanism of tangential-fired boiler corrosion empirically. The most dominant corrosion mechanism of tangential-fired boiler waterwall was corrosion by sulfur contained in the unburned carbon. And the secondary mechanism was $H_2S$ gas corrosion at localized reducing atmosphere. It is required to decrease the air-stage combustion operation in order to mitigate the waterwall tube corrosion. Also stringent coal pulverization quality control and reinforcing work for corrosion susceptible area such as anti-corrosion coatings is required

• Journal of Ocean Engineering and Technology
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• v.27 no.4
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• pp.83-89
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• 2013

A numerical scheme based on a mode superposition method is presented for the dynamic response analysis of a top-tensioned riser (TTR) under sheared current loads. The natural frequencies and mode shapes of the TTR have been calculated analytically for a beam with a slowly varying tension and pinned-pinned boundary conditions at the top and bottom ends. The lift coefficients and corresponding amplitudes used to estimate the vortex-induced modal force and damping for each mode were predicted via iterative calculations based on the input and output power balancing concept. Here, the power-in regions were controlled by the normal distribution function, for which the center was coincident with the lock -in location by local vortex-shedding, and the range was defined by the constant standard deviation for the reduced velocity by the local current speed. Finally, dynamic responses such as root-mean-squared displacement and stress were calculated using the mode superposition technique. In order to verify the presented scheme, a numerical calculation was performed for a TTR under an arbitrary linearly sheared current and linearly varying tension. A comparison with the results of the existing software showed that the presented scheme could give reliable and feasible solutions. Case studies were performed to investigate the effects of various current loads and tensions.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.3
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• pp.145-152
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• 2003

Electrical gate and drain characteristics of double heterostructure InAlAs/InGaAs pseudomorphic HEMTs have been investigated under sub-bandgap photonic excitation ($hv). Drain $(V_{DS})-,{\;}gate($V_{DS})-$, and optical power($P_{opt}$)-dependent variation of the abnormal gate leakage current and associated physical mechanisms in the PHEMTs have been characterized. Peak gate voltage ($V_{GS,P}$) and the onset voltage for the impact ionization ($V_{GS.II}$) have been extracted and empirical model for their dependence on the $V_{DS}$ and $P_{opt} have been proposed. Anomalous gate and drain current, both under dark and under sub-bandgap photonic excitation, have been modeled as a parallel connection of high performance PHEMT with a poor satellite FET as a parasitic channel. Sub-bandgap photonic characterization, as a function of the optical power with $h\nu=0.799eV$, has been comparatively combined with those under dark condition for characterizing the bell-shaped negative humps in the gate current and subthreshold drain leakage under a large drain bias.

• Journal of Power Electronics
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• v.16 no.2
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• pp.643-653
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• 2016

The conventional methods used to evaluate battery state-of-charge (SOC) cannot accommodate the chemistry nonlinearities, measurement inaccuracies and parameter perturbations involved in estimation systems. In this paper, an impedance-based equivalent circuit model has been constructed with respect to a LiFePO₄ battery by approximating the electrochemical impedance spectrum (EIS) with RC circuits. The efficiencies of approximating the EIS with RC networks in different series-parallel forms are first discussed. Additionally, the typical hysteresis characteristic is modeled through an empirical approach. Subsequently, a methodology incorporating an H-infinity observer designated for open-circuit voltage (OCV) observation and a hysteresis model developed for OCV-SOC mapping is proposed. Thereafter, evaluation experiments under FUDS and UDDS test cycles are undertaken with varying temperatures and different current-sense bias. Experimental comparisons, in comparison with the EKF based method, indicate that the proposed SOC estimator is more effective and robust. Moreover, test results on a group of Li-ion batteries, from different manufacturers and of different chemistries, show that the proposed method has high generalization capability for all the three types of Li-ion batteries.